Fair queueing algorithms for packet scheduling in BISDN

Abstract

This paper discusses several algorithms related to fair queueing and studies the application of fair queueing to the provision of quality of service (QOS) in broadband multi-media networks. We develop an intuitive understanding of several recent packet scheduling algorithms related to fair queueing, and show that one of them, the self-clocked fair queueing (SCFQ) algorithm, is both technically correct and practically implementable. The SCFQ algorithm provides a good analytic bound on delay, even in a multi-hop network; provides a bound on the discrepancy in service among sources (i.e., fairness); and provides isolation between sources to guarantee each source access to its allocated resources. The only computationally complex part of the algorithm is a sorting function, which can be implemented in hardware. We conclude that fair queueing provides a feasible and reliable way of satisfying QOS requirements for diverse traffic sources and applications, while maintaining a high level of network utilization. These properties make fair queueing a useful component of ATM network technology.KeywordsFair QueueingPacket SchedulingATMBISDNQuality of Service